A low developed east of Fraser Island and moved south. Hpeak and Hsig on the Southport wave rider bouy on the 4th were 6.7 m and 3.5 m. Two men were lost when a 8.1 m fishing boat was wrecked by a large wave on Breaksea Spit north Fraser Island early on th 6th.

 This event is classified as an East Coast Low.

More about East Coast Lows

Harden Up
Bureau of Meteorology
The Centre for Australian Weather and Climate Research report